The present invention relates to anchoring bolts embedded in concrete for anchoring a plate or the like to a concrete surface.
Anchoring bolts have been widely used in the construction field for securing plates or to support structures to a concrete surface. In the past, anchoring bolts that have been embedded in concrete have generally been set at the time of the concrete pour or have been placed after the concrete has been poured and dried by drilling a bore and anchoring the bolt in the bore in the concrete. Correct placement of the anchoring bolts in relation to measured locations and for the correct depth into the concrete has proved costly. The obstruction created by prior anchoring bolts placed during the concrete pour has caused a problem by hampering the finishing operation when trying to produce a flat plane on the surface of the concrete in the area of the protruding anchor bolt. Placement of the anchor bolts is difficult when the bolt placement is required to be further into the slab area than can be reached from the exterior of the pour.
Different types of anchor bolt assemblies have been used in the construction field for securing a support structure or plate to a concrete surface and these include an anchor bolt assembly for inserting and attaching into a drilled bore in cured concrete. This has been commonly done by having an expandable portion of the bolt attached to a threaded stud or bolt which is placed in the bore formed in the concrete and applying a torque to the working part on the end of the bolt to cause rotation of the bolt and a radial widening of the expandable portion into engagement with the hard concrete surface on the inside of the bore. A second type of anchoring bolt assembly uses an adhesive or grouting material within the bore hole for securing the bolt in place when the resin or grouting material has sufficiently hardened. The working part on the outer end of the bolt is rotated to torque an anchoring section embedded in the grouting material.
Typical prior art bolt anchors for concrete can be seen in the U.S. Pat. No. 3,418,781 for a Bolt Anchor for Concrete which is adapted to be attached to a concrete form and to be embedded into the concrete after the concrete has set. This bolt anchor is a one-piece shell of thermal plastic material which has a bolt receiving socket therein so that the shell can be bolted to a concrete form before the concrete is poured. In the Worzala, Jr. U.S. Pat. No. 4,726,561, a Concrete Insert Apparatus is adapted to be embedded in concrete and has an internally threaded bore having a nail head end placed in the bore with the nail pointed end extending outwardly from the bore. The threaded bore is filled with wax to hold the nail in place so that the nail can be attached to a mold form for support during the pouring of the concrete and then the wax and nail removed once the concrete is cured. The Ogden U.S. Pat. No. 1,365,718, shows an Adjustable Concrete Insert with a threaded bore which attaches to a board for support during a concrete pour. The Sandin U.S. Pat. No. 3,333,388, is for a Concrete Block Anchoring Means for a Wall Plate or Cap and has a threaded bolt member threaded into a sleeve anchored in a bore in concrete within a concrete block. The Barton U.S. Pat. No. 1,145,462, is a Socket for Concrete Construction which has a spring-like member anchored in the concrete for threading a threaded screw member thereinto. The Kesselman U.S. Pat. No. 5,228,250, is for a Tamper Proof Anchor Bolt Assembly of the type inserted into a drilled bore in concrete with an expanding end portion for locking the expandable anchor into the bore. The Neptune U.S. Pat. No. 2,772,560, teaches a Pickup Device for Precast Concrete Slabs which anchors a bolt screwed into a nut in a poured concrete slab member for anchoring a bracket or the like. The Kowell U.S. Pat. No. 3,764,066, is for a Concrete Railroad Tie Product and includes a threaded insert member for placement in a mold for receiving poured concrete, which member has a threaded member that threads thereinto.
In contrast to some of the prior art anchoring bolts, the present anchoring bolt is directed towards providing an improved anchor bolt which is inexpensively manufactured and easily placed prior to pouring the concrete and which is easily adjusted for the correct embedment depth. The anchoring bolt allows for the preplacement of the anchor bolt to insure correct bolt placement so that placement of the bolt can be correctly measured for height and location prior to the pouring of the concrete and has an adjustable bolt passing through an embedded sleeve which can be adjusted to insure a secure tie-down for members being fastened to a concrete surface. After the concrete has dried, the threaded bolt may be threaded up to the desired height for attaching a plate to the surface of the concrete.